Phase transition in nickel sulphide nanoparticles

The NiS nanoparticles were synthesised by the microwave-assisted chemical precipitation method. The XRD pattern shows that the prepared NiS nanoparticles have an orthorhombic structure. The SEM image of NiS nanoparticles confirms the nanostructure. The energy-dispersive X-ray analysis confirms the existence of Nickel and Sulphur in a proper ratio. The D.C. electrical resistances were measured in the temperature range 300 K–500 K. Oscillations were found in the temperature resistance curve of Nickel Sulphide nanoparticles on repeated heating and cooling due to phase transition. The XRD pattern of the powdered form of the NiS pellet used for the resistance measurement also confirms this phase transition. The two forms of UV and PL spectra of NiS nanoparticles were studied.